Recombinant DNA Advisory Committee - 6/9-10/94 
allow the proposed transduction procedure. The investigators have provided adequate 
data in response to toxicology questions relating to the long-term effect in an animal 
model. He recommended approval of the protocol. 
Other Comments 
Dr. Post asked the following questions: (1) Was the transduced FACC gene continuously 
expressed during the course of 6 month murine experiments? (2) Was the FACC gene 
expressed in cell colonies growing out of the transduced human CD34( + ) peripheral 
blood cells? 
Investigator Response-Dr. Liu 
Dr. Liu responded to several issues regarding quantitation of FACC RNA. FACC RNA 
was detected by the reverse transcriptase polymerase chain reaction (RT-PCR) assay of 
murine peripheral blood cells. Northern Blot analysis demonstrated low level FACC 
expression that was detectable at the end of the 6 month murine experiment. DNA PCR 
was used to demonstrate the presence of the transgene in human bone marrow cells. A 
functional assay was employed to determine improved colony growth. Data was 
presented on 3 Fanconi anemia cell lines representing 3 different mutations of the FACC 
gene. Normalization of mitomycin sensitivity was demonstrated by transduction of 
FACC gene into the cell line containing a stop codon mutation of the FACC gene. The 
corrected Fanconi CD34( + ) cells had a growth advantage over the defective cells, a fact 
that would favor engraftment of the transduced cells. Data was presented demonstrating 
transgene expression of transduced lymphoblast cell lines as well as cells of Fanconi 
anemia patients. The investigators looked at this sensitivity to mitomycin C in terms of 
chromosomal aberration and found that after gene correction, creation of cytogenetic 
abnormalities was reduced to normal. Data indicates that FACC is not an oncogene but 
plays a role in DNA repair. Fanconi anemia cells have an unusually prolonged G2 cell 
cycle phase. Introduction of the FACC gene into these cells diminishes the chance that 
cells with unrepaired DNA will enter into mitosis. 
Committee Motion 
The RAC approved a motion made by Dr. Parkman and seconded by Dr. Smith to 
accept the protocol submitted by Drs. Johnson M. Liu and Neal S. Young of the 
National Iiistitutes of Health, Bethesda, Maryland, by a vote of 13 in favor, 0 opposed, 
and no abstentions. 
XI. AMENDMENT TO PART I-D OF THE POINTS TO CONSIDER IN THE DESIGN 
AND SUBMISSION OF PROTOCOLS FOR THE TRANSFER OF RECOMBINANT 
DNA INTO THE GENOME OF ONE OR MORE HUMAN SUBJECTS (POINTS TO 
CONSIDER) OF THE NIH GUIDELINES REGARDING INFORMED CONSENT/DR. 
ZALLEN 
Dr. Zallen provided background information about the efforts of the Working Group on 
Recombinant DNA Research, Volume 19 
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